Super microfibrillated cellulose, process for producing the same, and coated paper and tinted paper using the same

• US 6,183,596 B1
• Filed: 07/01/1997
• Issued: 02/06/2001
• Est. Priority Date: 04/07/1995
• Status: Expired due to Term

• Current Assignee: Tokushu Paper Mfg. Co., Ltd. (Tokushu Tokai Paper Company Limited)
• Original Assignee: Tokushu Paper Mfg. Co., Ltd. (Tokushu Tokai Paper Company Limited)
• Inventors: Ueno, Katsuhiko, Matsuda, Yuji, Hirose, Mariko
• Primary Examiner(s): Chin, Peter
• Application Number:
  US08/886,262
• Time in Patent Office: 1,316 Days
• Field of Search: 162/9, 162/100, 162/176, 162/187
• US Class Current: 162/9
• CPC Class Codes: D21C 9/007 by mechanical or physical means
• CPC Class Codes: D21D 1/36 with vertical shaft
• CPC Class Codes: D21H 11/18 Highly hydrated, swollen or fibrillatable fibres
• CPC Class Codes: D21H 21/28 Colorants ; Pigments or opacifying agents
• CPC Class Codes: D21H 27/38 at least one of the sheets having a fibrous composition differing from that of other sheets

Abstract

A super microfibrillated cellulose having an arithmetic average fiber length of 0.05 to 0.1 mm, a water retention value of at least 350%, a rate of the number of fibers not longer than 0.25 mm of at least 95% based on the total number of the fibers as calculated by adding up, and an axial ratio of the fibers of at least 50. The super microfibrillated cellulose is produced by passing a slurry of a previously beaten pulp through a rubbing apparatus having two or more grinders which are arranged so that they can be rub together to microfibrillate the pulp to obtain microfibrillated cellulose and further super microfibrillate the obtained microfibrillated cellulose with a high-pressure homogenizer to obtain the super microfibrillated cellulose. A coated paper produced with a coating material containing the super microfibrillated cellulose, and a tinted paper produced from a paper stock containing the super microfibrillated cellulose as a carrier carrying a dye or pigment are also provided.

Claims

1. A super microfibrillated cellulose having an arithmetic average fiber length of 0.05 to 0.1 mm, a water retention value of at least 350%, the number of fibers not longer than 0.25 mm being at least 95% based on the total number of the fibers, and an axial ratio of the fibers of at least 50.